Rigid Flex – How to compare cost to traditional PCB’s

Moving to a rigid flex design from the traditional approach of using cable assemblies to join two or more PCB’s has obvious benefits including:   the ability the fit into a smaller form factor, less weight, increased bandwidth and increased current carrying capabilities.

A common question that we are asked is how to compare the cost of a rigid-flex with the traditional approach.    Typically, if you look only at the PCB cost, a rigid flex construction is going to be more expensive.  But after reviewing the overall cost of the assembly, very often there is a cost savings.

The following list is not meant to be all-inclusive.  Every application will be unique.  Our hope is that this list helps facilitate the thought process when doing a comparison of the two technologies.

Things to think about when comparing the total cost of an assembly:

• You are merging multiple boards into 1 design

• Cost of cables and connectors
  • Rigid PCB’s
  • Connectors
  • Wire/Cable
  • Wire Markers
  • Shrink Tubing
  • Cable Ties/ Fasteners
  • Freight

 

• Cost of the assembly operation.  You can now run one assembly instead of 2 or 3
  • Kitting for assembly
  • Labor
  • In Process Inspection
  • Cable Assembly Test
  • On Board/ Final Test
  • PCB Tooling/Test
  • Misc. costs – engineering time, etc.

 

• Testing:  Possibility of one test operation AND the ability to test the full assembly prior to installation

 

• Reliability
  • The flex connector is now an integral part of the board
  • No solder connections between boards
  • Reliability comes from a good design

• Order Processing Costs
  • Purchase order generation
  • Receiving
  • Incoming Inspection
  • Material Handling/ Storage

As I mentioned, this list is far from complete and meant to trigger discussion on the costs of a total assembly.  We are always here to help answer any questions or provide additional information on both cost comparisons and rigid flex design.   Visit our website at www.omnipwb.com.

 

 

Printed Circuit Board Stiffeners

Do you work with large profile PCB’s?  Do you work with thin PCB’s?  As the size increases, the printed circuit board can have issues with warp and bow creating challenges during assembly.  Handling can be an issue with thin boards.  If either of these issues sound like familiar struggles, check out  the new product we are working with;  “The Universal Stiffener”.

Typical PCB stiffeners are constructed with a rectangular bar with drilled holes.  But, that process can be expensive.  The Universal Stiffener reduces this expense with the design of an ingenious bar shape that will accept a screw anywhere along its length.  (They say a picture is worth 1,000 words so please see the attached picture.)

There is no need for a custom stiffener and the universal stiffener can be used with the existing tooling holes on your PCB.  There is no need to customize, you can adopt the new stiffener with no changes.

In addition to saving cost on the stiffener, there are a number of other benefits:

• The same bar will mount on PCB’s with different hole locations
• Eliminate close tolerances between mounting holes
• In most cases, the stiffener will occupy less PCB precious real estate
• Easy to install, no special tools required
• Can be mounted over insulated spacers to clear copper traces or wire adds
• Can be anodized different colors for coding
• Ideal PCB label area, when used on rear edge of PCB
• Strong and light-weight
• Can also be used as a heat sink or power/ground bus (use metal spacers and washers)

The Universal Stiffener comes in standard sizes and can be customized to the length you need.  The manufacturer is happy to provide samples and offer engineering advice to make sure the stiffener ordered is the best fit for you needs.  Check them out!   THE UNIVERSAL STIFFENER

Customer Service for PCB’s

We’ve been thinking a lot about customer service.  We know that people (including us) pay a lot of attention to customer service in their personal shopping experiences.  Who hasn’t complained about having to wait in line for even 5 minutes to check out at the grocery store?   Or thought, “Am I really happy to wait 60 minutes to have a pizza delivered”??    How about calling the telephone company for a quick service call and being met with automated responses with no way around it for the first 10 minutes.  We know, we’ve been there! 

It is not uncommon for us to choose one store over another based on the customer service and the overall experience while shopping there.   So how much attention is given to customer service in the electronics field, particularly in the PCB market?

We have worked in this industry for a very long time and have seen a wide range of customer service levels offered from different manufacturers.   The one thing they all have in common is that EVERY COMPANY THINKS they are giving the best customer service around.  Some do and many do not.   But in fairness, we are on the other side of the desk.  We have never purchased a PCB. 

This leads to the next question, what really IS important to the PCB “consumer”.  What attributes contribute to someone saying “I LOVE working with XXX Company for my printed circuit boards”.

What makes you feel like a valued customer? 

Is it time?  Quick response to RFQ’s, order confirmations, schedule changes, questions in general? 

Is it the overall communication?  Friendly, courteous, professional, being able to get to the right person, right away?  Easy to understand answers?

Is it quality?  Full quantities, no rejections, no issues about product meeting standards?

Is it design assistance?  DFM, consultation and recommendations, ease of resolution to engineering questions?

Is it feeling that your requirements are important?  A thank you when you place an order, follow up after shipment to make sure everything met your expectations, that your business matters?

Is it something else that we haven’t even thought of ??

What is the magic combination that makes PCB purchasing a positive experience instead of “something that has been done”??????

You can help OMNI to help you.

PCB Education – Have you checked out PCB Coffee Talk???

Printed Circuit Board Training– Have you checked out PCB Coffee Talk yet??

There is a lot to learn about PCB’s.  Designers have to keep up on new materials, surface finishes, and manufacturability guidelines to ensure the end product can be manufactured AND performs as expected.  Fabricators have to build to the PCB to customers’ specifications with good quality and on-time delivery.  Procurement needs to make sure the selected suppliers not only have the capability to manufacture the circuit board, but that they are selecting suppliers that provide the best overall value.

While each group has their own area of expertise, they are not mutually exclusive.   A new industry forum, PCB Coffee Talk provides a monthly webinar chat format addressing topics that fall into the over-lapping area of each specialty.

Each month, they sit down with an industry expert.  Topics to-date include surface finishes, micro via design, materials and PCB reliability.  The format is interactive and the attendees are encouraged to ask questions either during registration or during the webinar itself. 

If you are looking for a fun, interesting way to learn more about PCB’s and would like to have your questions answered by industry experts take 20 minutes and join the next session on March 28^th. 

The more people interacting during the webinar, the more entertaining and educational the sessions are!   Click HERE to register for the session on common fab notes and putting together the best quote package, or visit www.omnipcb.com to register or view past webinars.

Suggestions for future topics are always welcome!

Printed Circuit Board Stiffeners

Do you work with large profile PCB’s?  Do you work with thin PCB’s?  As the size increases, the printed circuit board can have issues with warp and bow creating challenges during assembly.  Handling can be an issue with thin boards.  If either of these issues sound like familiar struggles, check out  the new product we are working with;  “The Universal Stiffener”.  

Typical PCB stiffeners are constructed with a rectangular bar with drilled holes.  But, that process can be expensive.  The Universal Stiffener reduces this expense with the design of an ingenious bar shape that will accept a screw anywhere along its length.  (They say a picture is worth 1,000 words so please see the attached picture.)

There is no need for a custom stiffener and the universal stiffener can be used with the existing tooling holes on your PCB.  There is no need to customize, you can adopt the new stiffener with no changes.

In addition to saving cost on the stiffener, there are a number of other benefits:

• The same bar will mount on PCB’s with different hole locations
• Eliminate close tolerances between mounting holes
• In most cases, the stiffener will occupy less PCB precious real estate
• Easy to install, no special tools required
• Can be mounted over insulated spaces to clear copper traces or wire adds
• Can be anodized different colors for coding
• Ideal PCB label area, when used on rear edge of PCB
• Strong and light-weight
• Can also be used as a heat sink or power/ground bus (use metal spacers and washers)

The Universal Stiffener comes in standard sizes and can be customized to the length you need.  The manufacturer is happy to provide samples and offer engineering advice to make sure the stiffener ordered is the best fit for you needs.  Check them out!   THE UNIVERSAL STIFFENER

Buying Printed Circuit Boards Should Not Be Difficult!

Do engineering questions drive you crazy? 

Here is a common scenario:  You have a quote for 3 different part numbers and place a purchase order for delivery in 5 days.  A few hours later, you receive the dreaded email listing issues with the designs that need to be cleared up prior to manufacturing.  Then it takes a day or two of emails with your customer or your design engineer and your supplier to resolve the issue.  Then you are informed that your delivery will need to be pushed out for the 2 day delay in answering the questions!  Ugh.  Now the schedule has to be adjusted, the components you are paying a premium to receive in time for the build schedule will be sitting there, and your customer is NOT HAPPY.

This scenario occurs time and time again across a range of suppliers and a range of technology.  Nobody is really surprised, but MOST ARE FRUSTRATED! 

Sadly, at least 90% of designs that go through CAD/CAM and tooling at a PCB fabricator have questions that must be answered to manufacture the PCB properly.    Some are minor and can be answered quickly; others can require a partial or complete redesign of the PCB. 

Chapters could be written on ideas to improve this situation, but for today, I want to offer a few tips to keep in mind when working on a very tight schedule with critical delivery requirements.

•  Work with your supplier ahead of releasing the PO.  A good supplier will be happy to run a design for manufacturability review to catch any issues prior to the purchase order being released.  This may not catch everything up front, but it will catch the major issues that will cause delivery delays.

•  When you receive questions from the CAD/CAM tooling group, ask if this includes all questions associated with the design.  Sometimes two different engineers may be working on the same design to meet a quick turn delivery and both may have questions in their portion of the process.  Other times, when the initial issues are encountered, the job is set aside only to find additional issues when work is resumed.  The process can be streamlined by taking all questions to your designer or your end customer at one time.

•  If the questions are fairly involved, it is always best to try to schedule a conference call between your fabricators tooling group, your designer or end customer and yourself to resolve the issue as quickly as possible.  Email offers a great documentation trail for any changes, but can drag the process out longer than is necessary.  Just make sure someone is responsible for documenting the discussion.

• Once the questions are answered, follow up with your supplier to confirm that the questions involved in the tooling process have not impacted your delivery schedule.  You do not want to be surprised on the day you are expecting your printed circuit boards!

www.omnipcb.com

Printed Circuit Board Sourcing Strategy, are you guilty?

Printed circuit boards are typically the most expensive component and arguable the most important due to their functionality and criticality.  Yet, the typical PCB strategy follows the same structure as sourcing office supplies.  Does that make sense?

A typical PCB sourcing strategy looks like this:

• Typically treated as a commodity versus a custom component
• Procurement strategy is often made at a tactical, not a strategic level
• Many are doing business without a full understanding of capabilities, capacity or financial situation of their suppliers
• Maintain static strategies in a dynamic market
• Same strategy is used for domestic and off shore sourcing.  “One size fits all”

Results of the typical PCB sourcing strategy:

Under-optimization of the supply chain due to poor matching of PCB requirements with the suppliers “sweet spot”. 

The fact is, it is extremely rare for a company to have a homogenous technology level across their entire PCB demand.  There may be a few 2-4 layer designs, a few 12 layer designs, a difficult motherboard design, and maybe even a few flexible circuits.

It is also a fact that PCB fabricators have a “sweet spot” that best fits their equipment set, engineering expertise, size and company culture.   Although, very often, looking at their brochure or website will give the impression that they provide a full range of technology:  2 layer to 20 layer, .010” drill to micro via, standard materials to specialty materials, quick turn prototype through volume production.   At the end of the day, nobody wants to turn away business.

The result of not matching your requirements to a suppliers “sweet spot” can be:

• Increased risk in terms of price stability and performance
• Increased risk of supply chain disruption
• Increased overall cost

A few facts

• Very few organizations have a homogenous group of PCB requirements
• Only portions of a customer’s  PCB requirements are interesting to a good supplier
• Only 6.5% of PCB production is in the Americas
• Asia PCB suppliers do not operate in the same manner as North American based suppliers.

Do you need to revamp your PCB strategy?  Where do you start?

You start with the basics.  First, review your PCB technology and volume requirements.  Your requirements can then be segmented by attributes such as standard technology, HDI, heavy copper, flexible circuits, etc.  Then search to match suppliers to these requirements for both technology and volume.   Ask the tough questions to REALLY understand type of work suppliers excel at.

Next, make sure that you have fully developed your procurement spec.  Does it clearly spell out your requirements?  Are any of your requirements adding unnecessary expense?  All too often, a corrective action implemented for an issue that happened 10 years ago is driving a requirement that increases cost and just isn’t necessary in today’s manufacturing environment.

When the product arrives, are your inspectors fully trained to the IPC A-600 criteria?  Customer and supplier should be inspecting to the very same criteria.

Finally, supplier performance metrics should be in place with a regular review with your suppliers to provide feedback and create a continuous improvement loop.  Don’t just give your suppliers feedback on their performance to you, ask them for their opinion on how you can improve your designs and your procurement process.  You just might be surprised!

www.omnipcb.com